feat: implement UTDFN-4-EP(1x1) footprint

src/fn/index.ts

@@ -1,4 +1,5 @@
 export { dip } from "./dip"
+export { pdip } from "./pdip"
 export { diode } from "./diode"
 export { cap } from "./cap"
 export { led } from "./led"
@@ -81,3 +82,4 @@ export { sot343 } from "./sot343"
 export { m2host } from "./m2host"
 export { mountedpcbmodule } from "./mountedpcbmodule"
 export { to92l } from "./to92l"
+export { utdfn4ep1x1 } from "./utdfn4ep1x1"

src/fn/utdfn4ep1x1.ts

@@ -0,0 +1,171 @@
+import type {
+  AnyCircuitElement,
+  PcbCourtyardRect,
+  PcbSilkscreenPath,
+} from "circuit-json"
+import { z } from "zod"
+import { length } from "circuit-json"
+import type { NowDefined } from "../helpers/zod/now-defined"
+import { rectpad } from "../helpers/rectpad"
+import { base_def } from "../helpers/zod/base_def"
+import { type SilkscreenRef, silkscreenRef } from "src/helpers/silkscreenRef"
+
+const utdfn4ep1x1_def = base_def.extend({
+  fn: z.string(),
+  num_pins: z.union([z.literal(4)]).default(4),
+  w: z.string().default("1mm"),
+  h: z.string().default("1mm"),
+  p: z.string().default("0.5mm"),
+  pl: z.string().default("0.28mm"),
+  pw: z.string().default("0.22mm"),
+  ep: z
+    .union([z.literal(true), z.object({ x: z.string(), y: z.string() })])
+    .default(true),
+})
+
+type Utdfn4ep1x1Input = z.infer<typeof utdfn4ep1x1_def>
+
+/**
+ * Ultra-Thin Dual Flat No-Lead with Exposed Pad, 4-pin, 1x1mm
+ *
+ * Pins on left and right sides, with a thermal/ep exposed pad at the bottom center.
+ */
+export const utdfn4ep1x1 = (
+  raw_params: Utdfn4ep1x1Input,
+): { circuitJson: AnyCircuitElement[]; parameters: any } => {
+  const def = utdfn4ep1x1_def
+  const parameters = def
+    .transform((v) => {
+      const w = length.parse(v.w)
+      const h = length.parse(v.h)
+      const p = length.parse(v.p)
+      const pl = length.parse(v.pl)
+      const pw = length.parse(v.pw)
+      if (!v.ep) return v
+      return {
+        ...v,
+        w,
+        h,
+        p,
+        pl,
+        pw,
+      } as NowDefined<typeof v, "w" | "h" | "p" | "pl" | "pw">
+    })
+    .parse(raw_params)
+
+  const w = parameters.w
+  const h = parameters.h
+  const p = parameters.p
+  const pl = parameters.pl
+  const pw = parameters.pw
+
+  const pads: AnyCircuitElement[] = []
+
+  // Left side pins (1, 2) - going top to bottom
+  // Right side pins (3, 4) - going bottom to top
+  // Based on getCcwSoicCoords: pin 1 is top-left, pins increase CCW
+  for (let i = 0; i < parameters.num_pins; i++) {
+    const pn = i + 1
+    const ph = parameters.num_pins / 2
+    const isLeft = pn <= ph
+    const leftPinGaps = ph - 1
+    const gs = p
+    const sh = gs * leftPinGaps
+
+    let x: number
+    let y: number
+
+    if (isLeft) {
+      x = -w / 2 - pl / 2
+      y = sh / 2 - (pn - 1) * gs
+    } else {
+      x = w / 2 + pl / 2
+      y = -sh / 2 + (pn - ph - 1) * gs
+    }
+
+    pads.push(rectpad(pn, x, y, pl, pw))
+  }
+
+  // Exposed pad (thermal pad)
+  if (parameters.ep) {
+    const epw = 0.55 // exposed pad width
+    const eph = 0.35 // exposed pad height
+    pads.push(rectpad(["thermalpad"], 0, 0, epw, eph))
+  }
+
+  // Silkscreen body outline
+  const silkscreenPaths: PcbSilkscreenPath[] = []
+  const m = Math.min(1, p / 2)
+  const sw = w
+  const sh = (parameters.num_pins / 2 - 1) * p + pw + m
+
+  // Pin 1 marker (top-left corner arrow)
+  const as = p / 4
+  const atx = -sw / 2 - as / 2
+  const aty = sh / 2 - p / 2
+
+  silkscreenPaths.push({
+    layer: "top",
+    pcb_component_id: "",
+    pcb_silkscreen_path_id: "",
+    route: [
+      { x: atx, y: aty },
+      { x: atx - as, y: aty + as },
+      { x: atx - as, y: aty - as },
+      { x: atx, y: aty },
+    ],
+    type: "pcb_silkscreen_path",
+    stroke_width: 0.1,
+  })
+
+  // Silkscreen corners (DFN-style)
+  for (const corner of [
+    { dx: -1, dy: 1 },
+    { dx: -1, dy: -1 },
+    { dx: 1, dy: -1 },
+    { dx: 1, dy: 1 },
+  ] as const) {
+    const { dx, dy } = corner
+    silkscreenPaths.push({
+      layer: "top",
+      pcb_component_id: "",
+      pcb_silkscreen_path_id: "",
+      route: [
+        { x: (dx * sw) / 2 - dx * p, y: (dy * sh) / 2 },
+        { x: (dx * sw) / 2, y: (dy * sh) / 2 },
+        { x: (dx * sw) / 2, y: (dy * sh) / 2 - dy * p },
+      ],
+      type: "pcb_silkscreen_path",
+      stroke_width: 0.1,
+    })
+  }
+
+  const silkscreenRefText: SilkscreenRef = silkscreenRef(0, sh / 2 + 0.4, sh / 12)
+
+  const courtyardPadding = 0.25
+  const padExtentX = w / 2 + pl / 2
+  const padExtentY = sh / 2
+  const crtMinX = -padExtentX - courtyardPadding
+  const crtMaxX = padExtentX + courtyardPadding
+  const crtMinY = -padExtentY - courtyardPadding
+  const crtMaxY = padExtentY + courtyardPadding
+  const courtyard: PcbCourtyardRect = {
+    type: "pcb_courtyard_rect",
+    pcb_courtyard_rect_id: "",
+    pcb_component_id: "",
+    center: { x: (crtMinX + crtMaxX) / 2, y: (crtMinY + crtMaxY) / 2 },
+    width: crtMaxX - crtMinX,
+    height: crtMaxY - crtMinY,
+    layer: "top",
+  }
+
+  return {
+    circuitJson: [
+      ...pads,
+      ...silkscreenPaths,
+      silkscreenRefText,
+      courtyard,
+    ] as AnyCircuitElement[],
+    parameters,
+  }
+}